Radiance refers to the amount of light or radiant energy emitted, reflected, or transmitted by a surface in a particular direction. It is a measure of the brightness of a surface and is often used in the field of optics and radiometry to characterize the intensity of light at a given point.

Common examples of units related to radiance include watts per square meter per steradian (W/m²/sr) and watts per square centimeter per steradian (W/cm²/sr).

• Radiance is crucial in determining the intensity of light in various applications such as:
• Remote sensing and imaging technologies
• Solar energy collection and photovoltaic systems
• Climate studies and atmospheric science.